Many people find it difficult to feed themselves with conventional cutlery due to their physical status. Young children may find it frustrating to try to emulate their parents' use of forks and spoons at the dinner table. More often, the parents of those children have found it taxing to endure the constant spillage of food while indoctrinating the youngsters in the proper use of the forks and spoons. Before the age of eighteen months, many children are still struggling to develop the physical coordination necessary to master adult-style eating habits.
Adults may also have trouble using common cutlery. Some diseases, such as cerebral palsy (CP) and Parkinson's, and injuries to the spinal column can result in partial impairment of motor skills which make feeding one's self difficult, if not impossible. Parkinson's and CP cause uncontrollable tremors in the arms which make it difficult to hold liquid on a spoon or to aim a fork at a given piece of food. Spinal column injuries (or other kinds of nerve damage for that matter) can result in an ability to only partially control the movement of the arms; the possible range of motion is likely limited and eye-to-hand coordination may be affected. Other people are challenged by conditions caused by severe arthritis or arm injuries which simply limit the useful range of motion of their arms.
In the past, attempts have been made to solve these problems. The proposed solutions range from being very simple to very complex.
1) The Self-Leveling Spoons
So-called "self-leveling spoons" of various designs have been proposed to help disabled persons and young children feed themselves without spilling food excessively. U.S. Pat. No. 659,341 shows a self-leveling spoon which has a bowl 4 which rotates with respect to the handle 8. It has a single degree of rotational freedom about the longitudinal axis of the handle of the spoon. U.S. Pat. No. 2,682,705 shows a self-leveling spoon which has a bowl 1 which rotates with respect to the handle 6. It has a single degree of rotational freedom about the longitudinal axis of the handle of the spoon. It has a stop 10 which inhibits full 360 degree rotational freedom. U.S. Pat. No. 2,809,426 shows a self-leveling spoon which has a bowl 12 which rotates with respect to the handle 14. It has a single degree of rotational freedom about the longitudinal axis of the handle of the spoon. U.S. Pat. No. 4,389,777 shows a self-leveling spoon which has a bowl 4 which rotates with respect to the handle 2. It has a single degree of rotational freedom about the longitudinal axis of the handle of the spoon. It has sand or pebbles 62 inside the handle for weighting purposes. British patent document no. 833,889 (published May 4, 1960) and German patent document no. 2,005,351 (published Aug. 19, 1971) each show self-leveling spoons with a single degree of rotational freedom along the longitudinal axis of the spoon handle.
Some self-leveling spoon designs provided some means selectively holding the bowl of the spoon fixed with respect to the handle. U.S. Pat. No. 2,636,266 shows a spoon which has a bowl 1 which is selectively rotatable with respect to the handle 3. Rotation is along the longitudinal axis of the handle. Rotation is selectively inhibited by a mechanism internal to the handle (see elements 4, 14, 28 in FIGS. 3, 4, 6). U.S. Pat. No. 2,741,027 shows a spoon which has a bowl 16 which is selectively rotatable with respect to the handle 12. Rotation is along the longitudinal axis of the handle. Rotation is selectively inhibited by a mechanism internal to the handle (see elements 60, 62, 63, 74, 76, 78 in FIG. 10). U.S. Pat. No. 4,028,803 shows a self-leveling spoon which has a bowl 20 which rotates with respect to the handle 22. It has a single degree of rotational freedom about the longitudinal axis of the handle of the spoon. The disclosure emphasizes a mechanism for selectively inhibiting rotational movement of spoon with respect to the handle (see FIGS. 2 & 3). U.S. Pat. No. 4,993,156 shows a self-leveling spoon which has a bowl 10 which rotates with respect to the handle 24. It has a single degree of rotational freedom about the longitudinal axis of the handle of the spoon. The bowl is connected to a pendulum weight 22 which is located at the opposite end of the handle from the bowl. It also discloses a selectable locking mechanism 30, 32, 34.
It has been proposed to fasten a self-leveling spoon to the hand of the user with straps. U.S. Pat. No. 4,325,187 shows a self-leveling spoon which discloses a strap system (see especially element 12 in FIG. 5) for fastening the handle of the spoon to the user's hand. The bowl 18 has only a single degree of rotational freedom with respect to the handle 20, 32.
The most glaring limitation of the self-leveling spoons proposed thus far is the ability to rotate about only one axis. These spoons will operate marvelously if the axis of rotation of the user's hand happens to coincide precisely with the longitudinal axis of the spoon. If the user fails to accomplish this coincidence, the spoon will spill its contents just like an ordinary spoon. For most persons with impaired or undeveloped physical capacities, this is just too much to ask.
2) The Technically Complex Proposals
In the last decade, solutions of increasing sophistication have been proposed. U.S. Pat. No. 4,433,950 shows a motorized self-feeding apparatus which has a spoon B which is moved about by a complex mechanical linkage system (see FIGS. 1 & 3). U.S. Pat. No. 5,037,261 shows a motorized self-feeding apparatus which has a spoon 20 which is moved about by a complex mechanical linkage system. FIGS. 2 & 3 are most illustrative. U.S. Pat. No. 5,282,711 shows a robotic self-feeding apparatus which has a spoon 64 which is moved about by a complex mechanical linkage. The system is computer controlled. The devices proposed by these disclosures are of such a high level of complexity and sophistication that they would cost at least two orders-of-magnitude more to manufacture than ordinary spoons.
3) Other Miscellaneous Inventions
Forks have been disclosed which have tine portions which rotate with respect to their handles. However, it does not appear that these would be particularly helpful to persons with impaired motor skills. These inventions are directed toward solving the particular problem of eating spaghetti. U.S. Pat. No. 2,602,996 shows a fork which a prong and shank section 14 which rotates with respect to the handle 13. Rotation is along the longitudinal axis of the handle and is controlled by the user at thumb wheel 15. U.S. Pat. No. 4,599,797 shows a fork which a prong and shank section 14 which rotates with respect to the handle 12. Rotation is along the longitudinal axis of the handle and is controlled by the user at thumb wheel 18.
One dipping device has been proposed which allows rotation of the bowl with respect to the handle about plural axes. U.S. Pat. No. 1,545,365 shows a skimmer ladle which has a bowl 4 which rotates with respect to the handle 5. It has two degrees of rotational freedom which are about the orthogonal axes which are transverse to the longitudinal axis of the handle of the ladle. Rotation is controlled by the user via controls 20, 15, 10, 12. Although this ladle does allow movement with two degrees of rotational freedom, it has no self-leveling structure to prevent spilling.